Treatment allocation |
959 (100%) |
495 (51.6%) |
464 (48.4%) |
Age at randomization (years) |
33.5 (4.0) |
33.3 (4.0) |
33.8 (4.0) |
Age at ovum pickup (years) |
32.9 (4.1) |
33.1 (4.1) |
33.1 (4.1) |
Duration of subfertility (years) |
3.0 (2.3) |
2.9 (2.2) |
3.1 (2.5) |
Fertility status |
Primary subfertility |
383 (39.9%) |
196 (39.6%) |
191 (41.2%) |
Parity |
0 |
555 (57.9%) |
284 (57.4%) |
271 (58.4%) |
1 |
353 (36.8%) |
188 (38.0%) |
165 (35.6%) |
>2 |
51 (5.3%) |
23 (4.6%) |
28 (6.0%) |
Initial treatment |
IVF |
426 (44.4%) |
231 (46.7%) |
195 (42.0%) |
IVF–ICSI |
533 (55.6%) |
264 (53.3%) |
269 (58.0%) |
Outcome initial treatment |
Live birth |
242 (25.2%) |
116 (23.4%) |
127 (27.4%) |
Number of diagnoses |
One diagnosis |
879 (91.7%) |
452 (91.3%) |
427 (92.0%) |
Two diagnoses |
80 (8.3%) |
43 (8.7%) |
37 (8.0%) |
Diagnoses |
Unknown |
211 (20.6%) |
113 (21.3%) |
98 (19.9%) |
Severe male subfertility |
424 (41.4%) |
216 (40.7%) |
208 (42.2%) |
Moderate male subfertility |
129 (12.6%) |
55 (10.4%) |
74 (15.0%) |
Tubal factor |
140 (13.7%) |
79 (14.9%) |
61 (12.4%) |
Endometriosis Stage 1–2 |
40 (3.9%) |
23 (4.3%) |
17 (3.5%) |
Endometriosis Stage 3-4 |
24 (2.4%) |
13 (2.5%) |
11 (2.2%) |
Hormonal factor |
29 (2.8%) |
20 (3.8%) |
9 (1.8%) |
Cervical factor |
9 (0.9%) |
3 (0.6%) |
6 (1.2%) |
Other |
17 (1.7%) |
8 (1.5%) |
9 (1.8%) |
Number of IVF or IVF–ICSI treatment prior study ET |
0 |
521 (55.2%) |
274 (56.1%) |
247 (54.3%) |
1 |
259 (27.5%) |
127 (26.0%) |
132 (29.0%) |
2 |
141 (15.0%) |
73 (15.0%) |
68 (14.9%) |
3 |
22 (2.3%) |
14 (2.9%) |
8 (1.8%) |
Number of FET prior to study ET |
0 |
334 (34.9%) |
184 (37.2%) |
150 (32.5%) |
1 |
509 (53.2%) |
255 (51.5%) |
254 (55.1%) |
2 |
75 (7.8%) |
35 (7.1%) |
40 (8.7%) |
>3 |
38 (4.5%) |
21 (4.2%) |
17 (3.7%) |
Duration of cryopreservation (years) |
0.71 (1.0) |
0.65 (0.90) |
0.76 (1.0) |
Survival (%) |
72 |
74 |
70 |
Developmental stage at cryopreservation |
Cleavage stage (Day 3 or 4) |
886 (92.4%) |
454 (91.7%) |
432 (93.1%) |
Blastocyste stage (Day 5) |
73 (7.6%) |
41 (8.3%) |
32 (6.9%) |
Number of embryos transferred |
1.0 (0.6) |
1.0 (0.58) |
0.96 (0.61) |
Embryo quality score |
Good |
348 (40.0%) |
182 (39.0%) |
166 (40.9%) |
Reasonable |
288 (33.0%) |
158 (33.8%) |
130 (32.0%) |
Moderate |
196 (22.5%) |
102 (21.8%) |
94 (23.2%) |
Poor |
41 (4.7%) |
25 (5.4%) |
16 (3.9%) |
Endometrial thickness (mm) |
9.0 (1.8) |
9.0 (2.0) |
8.9 (1.6) |